Description
Primordial Gravitational Waves (PGWs) are a key prediction of inflation, with ongoing efforts to detect them through CMB polarization patterns and direct interferometric searches. In this talk, I will present a novel approach to probing PGWs through their impact on Large-Scale Structure (LSS). While PGWs are often assumed to have a negligible effect on structure formation, our study shows that they can source second-order scalar perturbations. These "tensor-induced scalar modes" emerge upon horizon entry, modifying the matter density contrast and leaving distinct imprints on the matter power spectrum. This mechanism also introduces an intrinsic source of non-Gaussianity in the density field, providing a unique observational signature. I will discuss how different PGW power spectra shape this imprint and evaluate its detectability in future galaxy surveys like Euclid and SKA.
